This invention relates to an apparatus for checking a failure in an evaporated fuel purging unit having a canister adapted to accumulate evaporated fuel from a fuel tank and introduce the evaporated fuel into the engine.
It has been proposed, for example, in Japanese Patent Publication No. 56-11067 to prevent leakage of evaporated fuel from a fuel tank to the exterior by employing an evaporated fuel purging unit of the type having a canister connected through a conduit to the fuel tank and also through a conduit to an engine induction passage. The canister contains adsorbent, such as activated charcoal, for adsorbing or accumulating fuel evaporated in the fuel tank. The accumulated fuel is introduced from the canister to the engine under a vacuum pressure in the induction passage.
When at least one of the conduits comes off or clogs, a great amount of evaporated fuel will flow to the exterior. However, the driver and/or passenger hardly notices such a failure in the evaporated fuel purging unit.